This invention relates to surgical devices, and more particularly to hysteroscopes for the observation and treatment of tissue abnormalities in the uterus of a female patient. The invention is also directed to endoscopic medical instruments in which a video camera is carried at the distal end of a flexible insertion tube.
Present day hysteroscopic techniques involve the use of a rather complex optical system which is inserted vaginally through the cervix, as are surgical instruments. With present day hysteroscopy, in order to observe through the optical system, the surgeon has to keep his or her face close to the affected area of the patient. Also, because of the rigid nature of the hysteroscope, it is possible to work most effectively only in the main body of the uterus, and it is difficult to operate in the horns of the uterus.
An endoscope, and in particular, a gastroscope, is generally characterized as an elongated flexible tube with a viewing head on its distal or forward end, and a control housing at the proximal end for controlling or steering the distal end. In a gastroscope, a bendable steering or articulation section is provided at the distal end adjacent the viewing head. This section extends proximally for a considerable distance to accommodate large bending angles. One or two pairs of control cables extend through the bendable steering section and the remainder of the flexible tube and connect with steering controls in the control section. One or both pairs of these cables are displaced in order to bend the bendable steering section, and thus change the angular orientation of the viewing head. A gastroscope, or any other type of endoscope, is typically inserted into a body cavity of a patient in order to visually investigate the tissues within the cavity. Because the esophagus, stomach, and upper intestinal track are narrow, tortuous passageways, and because of the need for retrospective viewing, the steering section of a gastroscope generally must articulate over an arc of at least 180 degrees. Also, in a gastroscope the insertion tube tends to have a rather stiff proximal section and a softer or more flexible distal section. A limited amount of water and air are channeled through the gastroscope and are directed across the viewing window of the video imager in the viewing head. Such gastroscopes are designed to emit only short bursts of liquid transversely across the glass window of the imager for cleaning of said window.
It would be desirable to employ an endoscope generally of the form of a gastroscope to perform as a hysteroscope for uterine surgery. It would be even more desirable for an endoscope to be insertable up into either of the two horns of the uterus. This would permit a surgeon to observe tissue abnormalities and to treat the same, e.g., with a therapeutic laser. Such a hysteroscopic endoscope should have flexibility which is mild enough to follow the curves of the uterus without damaging the uterine lining, yet stiff enough to permit insertion and accurate manipulation. Such a video endoscope would require a rather short working length, as compared with standard gastroscopes. Ideally, such an endoscopic instrument would employ the video camera in connection with a video monitor to permit a surgeon to work at a position where his or her face is remote from the affected area of the patient. The articulation section should also be as short as possible so that the video imager and laser fiber can be aimed and positioned accurately, even in low clearance areas within the uterine horns.
Unfortunately, no existing endoscopic instrument is suitable for performing such surgery within the uterus, nor has anyone previously adapted a flexible endoscope for this purpose.